Sarcasm is how I cope with stupidity. It beats drinking.
Anyhew, to say that the Bible was used for slavery, a book that starts with Moses leading the Hebrew people out of slavery, because most men back then were slaves, is asinine.
As for people, that is a different story. People are basically sheep as the Bible states.
The way people form their morality is from authority figures. This means your parents, your peers, the state, your preacher, etc. So one will have more influence than the others. For those not of faith, or those who say they are of faith but don't really practice their faith, the state usually controls their morality. This can be seen with both slavery and the abortion issue. When the state legalized slavery the consensus was that slavery is not ideal, but is Ok. However, years after being made illegal everyone pretty much views slavery as evil. And before abortion was made legal, the general consensus was that it was evil, but after being made legal all these years, the general consensus has likewise shifted to people saying that, although not ideal, it is Ok.
This is historical proof how the morality of the people can be easily manipulated, but most will refuse to admit they are lemmings. You know, pride and all.